Masonry has a high compressive strength but a limited tensile strength. This leads to limitations in the design of masonry (such as limited height, limited width, limited length of masonry) and may lead to cracking when tensile and/or shear stresses develop in the masonry.
Bed joint reinforcement, for example prefabricated bed joint reinforcement of steel meshwork, is a proven technology for allowing masonry to carry higher loads (e.g. wind loads) by providing additional strength and flexibility, and for controlling cracks in masonry that is subject to tensile forces.
Bed joint reinforcement of steel meshwork for structural use (according to definitions of EN 845:3) generally comprise welded wire meshwork, such as two parallel longitudinal wires connected by a continuous zig-zag wire (truss type) or connected by straight cross wires (ladder type).
Prefabricated bed joint reinforcement structures typically have a length of about 3 m, for example 2.70 m or 3.05 m. This relatively long length makes the transportation, storing and handling of the structures complex.
To secure continuous reinforcement and to avoid weak points in reinforced masonry, overlapping of neighbouring prefabricated bed joint reinforcement elements is necessary and common practice. Overlapping leads to higher material consumption as double amount of material is required in the overlap zones.
Furthermore, as overlaps between neighbouring bed joint reinforcement structures may not be located at areas of high stress or at areas where the dimensions of a section change (for example a step in a wall height or thickness), the work of the installer of bed joint reinforcement elements is complicated.